Car switching system

ABSTRACT

A car switching system for an operator-less railway transportation system in which the track is stationary and the switching is accomplished by a mechanism mounted on the cars. This mechanism may consist of oppositely disposed cam followers mounted for vertical displacement on each side of the car and interconnected so that the cam follower or followers on one side are up, out of engagement with the track, when the cam follower or followers on the other side are down, in engagement with the track.

United States Patent [191 Butzow [451 May21, 1974 CAR SWITCHING SYSTEM[75] Inventor: Neil William Butzow, Greendale,

Wis.

[73] Assigne'e: Rexnord Inc., Milwaukee, Wis.

22 Filed: Nov. 14, 1972 [21] App]. No.: 306,487

[52] US. Cl. 104/130, 246/427 [51] Int. Cl E0lb 25/06 [58] Field ofSearch 104/88, 96, 105, 130;

[56] References Cited UNITED STATES PATENTS 3/1972 Broome 104/130 Xll/l964 Anderson 104/88 7/l97l Marty 104/130 Primary Examiner-M. HensonWood, Jr.

Assistant Examiner-D. W. Keen Attorney, Agent, or Firm-Sughrue,Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT A car switching system foran operator-less railway transportation system in which the track isstationary and the switching is accomplished by a mechanism mounted onthe cars. This mechanism may consist of oppositely disposed camfollowers mounted for vertical displacement on each side of the carandinterconnected so that the cam follower or followers on one side areup, out of engagement with the track, when the cam follower or followerson the other side are down, in engagement with the track.

5 Claims, 5 Drawing Figures PATENTED HAY 2 1 mm HUI FIELD OF THEINVENTION The invention relates generally to the switching of cars fromone track to another in a railway-type transportation system and, morespecifically, to the switching of operator-less, remotely controlledcars in a transportation system such as is disclosed in commonlyassigned U.S. Pat. Nos. 3,62l,790 and 3,650,216.

BACKGROUND OF THE INVENTION To meet the demands of some transportationsystems, it is necessary or desirable to use a large number of smallcars, or carriers, rather than a few large carriers, or trucks. This isparticularly true where the freight to be carried by the transportationsystem must be sent to a large number of different destinations, butpromptness is required, so that it is not feasible to accumulate to anygreat extent different loads going to a common destination. Suchsystems, moreover,may be extremely heavily trafficked, as where they areused for baggage transportation in a major airport or mailtransportation in a large post office. In such situations, it isnecessary that mechanisms be provided to permit rapid, highly reliableselective switching of certain cars from one transportation line toanother without affecting the cars that are being sent straight through.The invention disclosed herein is such a mechanism.

SUMMARY OF THE INVENTION The moving parts of the mechanism disclosedherein for switching cars on a rail transportation system from onetransportation line to another are mounted on the cars. Broadlyspeaking, this is opposite to the type of switching used with railroadcars, in which the moving parts of the switching mechanism areassociated with the rails. The moving parts of the mechanism may consistof cam followers (1) oppositely disposed on the sides of the cars forcontact with a guide which may or may not be the track itself, (2)mounted for vertical displacement, and (3) interconnected so that thecam follower or followers on one side are up, out of engagement with theguide, while the cam follower or followers on the other side are down,in engagement with the guide. The guide on one side will lead the carinto one transportation line, and the guides on the other side will leadthe car into the other. The cam follower or followers are spring-biasedto be normally down on one side, but their disposition may be reversedby means of a movable switching ramp placed on one side of the guidewayprior to each switch. A fixed switching ramp placed on the opposite sideof the guideway after the switch on the transportation line into whichthe car is directed if the movable switching ramp has been used toreverse the disposition of the cam followers may be used to return thedisposition of the cam followers to normal.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a section oftrack including a switch.

FIG. 2 is a simplified drawing of a cross-section of a car running onthe track, showing the switching mechanism.

FIG. 3 is a side view ofa fixed switching ramp as seen from the lineIll-Ill in FIG. I.

FIG. 4 is a top view of a rail having an indentation to facilitatevertical displacement of the cam followers.

FIG. 5 is a cross-sectional view of the rail shown in FIG. 4 as seenfrom the line V-V therein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the preferredembodiment of this invention, at each switch the approach rails 10diverge, onerail following the'straight line, or through, track and theother following the siding. The two rails initiating at the switch arearranged according to the usual practice in railroading except for theomission of moving portions of the ordinary switch.This trackarrangement is shown in FIG. 1. I

A car approaching from the left is, if if is to pass straight through,forced to its right by means described hereinafter. This has twoeffects. First, it allows the flanges ll of the right-hand wheels 12 topass through the gap between the right-hand approach rail 10 and theswitch rail 13 initiating adjacent thereto. Second,'it forces theleft-hand wheels 15 to follow the switch rail 16 rather than thecontinuation of the left-hand approach rail 10. Correspondingly, if thecar is to follow the siding, or branch line, it is forced to the left asit approaches the switch, allowing the flange 14 of its lefthand wheels15 to pass through the gap between the left-hand approach rail 10 andthe switch rail 16 initiating adjacent thereto and forcing theright-hand wheels 12 to follow the switch rail 13 rather than thecontinuation of the right-hand approach rail 10. Plates 17 are providedin the switching areas to support the flanges of the wheels as thewheels cross the gaps in the track.

The switching of the cars at each switch point may be controlledautomatically in various ways. One way of controlling the switching isdescribed in commonly assigned U.S. Pat. Nos. 3,621,790 and 3,650,2l6,and an improvement thereof will be described herein.

In the presently preferred embodiment, the means for forcing the car tothe right or to the left, depending on whether it is desired to send thecar straight through or direct it to the siding, include twointerconnected pairs of cam followers 17 mounted, one pair to a side, oneach side of the car 18. These cam followers are adapted to contact withthe guides 19 and 20, mounted for vertical displacement, andinterconnected by any suitable means for insuring'that, when the'camfollowers on one side are up, the cam followers on the other side aredown. Thus, when a switch is encountered, the pair of cam followerswhich are down guide the car while the pair of cam followers which areup pass through the previously described gap in the track, taking nopart in the operation.

One suitable means for interconnecting the cam followers 17 is shown inFIG. 2. It consists of guide rods 21 and 22 vertically slidable intubular guides 23 and 24, arms 25 and 26, pivot rods 27 and 28, arms 29and 30, drag link 31, and spring detent 32. The spring detent 32cooperates with the end of arm 25 to hold the linkage at one end or theother of its travel.

The cars are normally conditioned to follow the lefthand branch at eachswitch, which may be a siding as shown in FIG. I or may be a throughtrack if the siding is to the right. Therefore, if it is desired to sendthe car into the right-hand branch, the vertical disposition of the camfollowers must be reversed. One suitable 3 means for accomplishing thisreversal is described in commonly assigned US. Pat. Nos. 3,621,790 and3,650,216, and another will now be described.

ln'the presently preferred embodiment, the means for reversing thevertical disposition of the cam followers consists of a movableswitching ramp 33 placed on the left side of the track prior to eachswitch. This ramp includes a plane 34 which is normally positionedbeneath the path of the left-hand cam followers 17 and means, such as anair cylinder, for pivoting the down track end'of the plane up into thepath of the cam followers. If a car is to be sent into the right-handbranch at the switch, the ramp is actuated by a predetermined signaloriginating either from a computer or from an escort memory system suchas is disclosed in commonly assigned US. Pat. Nos. 3,62l,790 and3,650,216. When the switching ramp is actuated and acar passes theswitching ramp, the cam followers on the left side of the car are forcedinto an up position and, by virtue of the linkage system shown in F IG.2, the cam followers on the right side of the car are forced into a downposition, causing the car to take the right-hand path in the mannerpreviously described.

After passing the switch, the lowered cam followers 17 on the right-handside of the car engage a fixed switching ramp 35 which forces the camfollowers on that side upwardly and, acting through the linkage, lowersthe cam followers on the left-hand side of the car, thereby returningthe cam switching mechanism to its normal position.

While the cams '19 and are shown to cooperate with cam followers 17, thefollowers may be positioned to'cooperate with the adjacent rails 10,provided that the followers can be located closely adjacent the wheelsand the curves inthe track are not too sharp. Otherwise it is difficultto locate the cam followers so that they will work on both a curved railand a straight rail.

lf the cam'followers are positioned to cooperate with the adjacent railsl0,moreover, they may be subject to wedging against the side of the railat the instant they are to be switched up or down. This wedging createsa tremendous resistance tothe displacement of the cam followers and canprevent the cam followers from moving to the desired vertical position.While the cam followersv could be made of extremely low frictionmaterial, this would be undesirable because it would allow the camfollowers to slide on the rail rather than to roll- .However, it hasbeen found that wedging may be 'prevented by running the cars on thelower flange of rails shaped like angle irons rather than onrailroad-type rails and placing indentations in the upright flange ofthe rails where vertical displacement of the cam follower is to takeplace. A rail 36 having such an indentation 37 is shown in F l6. 4. Whenthe car is in a position to start the vertical displacement of the camfollowers, the rail is indented slightly, allowing the cam followers toleave the rail. The displacement is then accomplished by the switchingramp with no wedging or friction problems between the cam followers andthe rail. To allow the car to travel this short distance in an unguidedmanner, graduated fillets 38 may be added to the rail just prior to theswitching area in order to remove the normal clearance between thewheels and the rails, thus insuring that the car will be moving in astraight line along the track when it enters the unguided area. FIGS. 4and 5 show a fillet on the same side of the rail as the indentation, butof course the fillet would be on the opposite side if the system weredesigned to have the wheel run on the opposite side of the rail from theside acting as the cam.

Although the specification has described only a preferred embodiment ofthe present invention, it will be obvious to those skilled in the artthat various changes in form and detail could be made therein withoutdeparting from the inventive concept.

What is claimed is:

1. Apparatus for selectively switching from one transportation line toanother a car adapted to travel in a prescribed path over thetransportation lines of a system of transportation lines the individuallines in which are interconnected at switches where one transportationline diverges into two, said apparatus comprising:

indentations at the point where the vertical dis- 1 placement of the camfollowers takes place in order to facilitate said vertical displacement.2. Selective switching apparatus as claimed in claim 1 wherein saidtransportation lines comprise rails, said car has wheels thereon whichare adapted for cooperation with said rails, and said guides are therails on which the car travels. v v

3. Selective switching apparatus as claimed in claim 2 wherein there isnormally a small amount of clearance between one side of said wheels andone side of said rails, but graduated fillets of maximum widthsufficient to remove said normal clearance are provided on thesaid sideof the said rails just priorto the indentations, thereby insuring thatthe car will be moving in a straight line along the track when it entersthe area of indentations.

4. Selective switching apparatus as claimed in claim I wherein the camfollowers are spring-biased to be normally down on one side and up onthe other, but their disposition may be selectively reversed by means ofa movable switching ramp. placed prior to each switch on the side ofsaid rails on which the one of said cam followers which is normally downis located.

5. Selective switching apparatus asclaimed in claim 4 wherein thedisposition of said cam follower is returned to normal by means of afixed switching ramp placed on the side of the rails opposite from theside on which said movable switching ramp is placed and after the switchon the transportation line into which thecar is directed if the movableswitching ramp has been used to reverse the normal disposition of thecam followers. t l i

1. Apparatus for selectively switching from one transportation line toanother a car adapted to travel in a prescribed path over thetransportation lines of a system of transportation lines the individuallines in which are interconnected at switches where one transportationline diverges into two, said apparatus comprising:
 1. a pair of camfollowers mounted one on each side of said car, said cam followers beingmounted for vertical disPlacement and interconnected so that when thecam follower on one side of the car is up, the cam follower on the otherside is down; and
 2. a pair of stationary guides positioned to cooperatewith said cam followers when in the down position only, one guideleading the car into one of said divergent transportation lines and theother guide leading the car into the other, said guides havingindentations at the point where the vertical displacement of the camfollowers takes place in order to facilitate said vertical displacement.2. Selective switching apparatus as claimed in claim 1 wherein saidtransportation lines comprise rails, said car has wheels thereon whichare adapted for cooperation with said rails, and said guides are therails on which the car travels.
 2. a pair of stationary guidespositioned to cooperate with said cam followers when in the downposition only, one guide leading the car into one of said divergenttransportation lines and the other guide leading the car into the other,said guides having indentations at the point where the verticaldisplacement of the cam followers takes place in order to facilitatesaid vertical displacement.
 3. Selective switching apparatus as claimedin claim 2 wherein there is normally a small amount of clearance betweenone side of said wheels and one side of said rails, but graduatedfillets of maximum width sufficient to remove said normal clearance areprovided on the said side of the said rails just prior to theindentations, thereby insuring that the car will be moving in a straightline along the track when it enters the area of indentations. 4.Selective switching apparatus as claimed in claim 1 wherein the camfollowers are spring-biased to be normally down on one side and up onthe other, but their disposition may be selectively reversed by means ofa movable switching ramp placed prior to each switch on the side of saidrails on which the one of said cam followers which is normally down islocated.
 5. Selective switching apparatus as claimed in claim 4 whereinthe disposition of said cam follower is returned to normal by means of afixed switching ramp placed on the side of the rails opposite from theside on which said movable switching ramp is placed and after the switchon the transportation line into which the car is directed if the movableswitching ramp has been used to reverse the normal disposition of thecam followers.